Posted
by
samzenpus
on Wednesday August 25, 2010 @09:53PM
from the frugal-cutting dept.

An anonymous reader writes "Peter Jansen, a PhD student and member of the RepRap community, has constructed a working prototype of an inexpensive table-top laser cutter built out of old CD/DVD drives as an offshoot of his efforts to design an under $200 open-source Selective Laser Sintering (SLS) 3D printer. Where traditional laser cutters use powerful, fixed-focus beams, this new technique dynamically adjusts the focal point of the laser using a reciprocating motion similar to a reciprocating saw, allowing a far less powerful and inexpensive laser diode to be used. The technique is currently limited to cutting black materials to a depth of only a few millimeters, but should still be useful and enabling for Makers and other crafters. The end-goal is to create a hybrid inexpensive 3D printer that can be easily reconfigured for 2D laser cutting, providing powerful making tools to the desktop."

I'm going to be up front and honest and tell you "I don't know". That said, I did see a video once where a guy took a blu-ray laser, macguyver'd it into a toy phaser pistol, and used it to pop black ballons.

I could be wrong, but wasn't the higher energy "potential" in bluray drives was used because of the slightly different disk construction, which required a bit more power to get a proper reflection in some parts as well as an attempt to fix problems with future RW disks that were visibly observable in CD and DVD drives?

I'm fairly certain that modern DVD drives have quite powerful red lasers as well, to facilitate reading from rather dim RW disks. Those should be rated to be capable of far greater power outpu

No, it was used because 405nm is a smaller wavelength, which means you don't need large pits in the plastic, you can use much smaller pits and thus pack more data onto a disc.

Lasers are not held to a standard for reading R/RW discs, the discs themselves have a certain reflectivity threshold they must adhere by to obtain that certification. Many discs were just crappy because they didn't have a proper reflective layer that didn't properly reflect the laser back. (Memorex, I'm looking at you with your hematit

C'mon. You can do better than that:
Yo mama is so fat she needs a laser cutter to clip her nails.
Yo mama is so ugly the laser light tries to bend around her.
Yo mama is so poor she needs a laser to cut the last slice of bread.
Yo mama is so stupid she uses a laser to light the house.

Always remember the warning that is on the first page of the manual.
"DO NOT LOOK INTO LASER WITH REMAINING EYE"

Several labs in my Uni's Chemistry Department regularly employ LASER choppers, if not "cutters". Simply stick the disk with the slits you want (to set the pulse duration) in front of the laser and set the motor to the desired RPM. That's how they get he pulse durations and frequencies that they need for their experiments. One could also use liquid crystal to turn the beam on and off rapidly. Come to think of it, I have no idea how a CD or DVD burner controls its laser. Maybe the laser can be turned on and off fast enough.

Laser diodes, used in CD/DVD/whatever have a terrible beam quality for cutting and a mostly inappropriate wavelength, but they can be switched on/off quite fast. Think of fiber optics...Other techs may be pretty slow to turn on/off, but have quite good beam quality for cutting. The most widely used is CO2 laser for that, which can take from 100's of us to a couple ms to turn on/off. With these lasers it's faster to move it optically away with mirrors of defocussing with lenses.

It's a reference to the MakerBot [makerbot.com]. It's a RepStrap, a way to build yourself a RepRap if you don't yet own a one. I've got one on my desk upstairs, waiting for a replacement thermistor for my extruder so I can start churning out parts for this one. [reprap.org]

The fact that you can get one in a kit form has spawned a whole host of different printable upgrades for the MakerBot. For example, there's a set of models up on thingiverse you can download and print that will let you mount a Dremel tool in place of the print

Who will eventually start suing anyone using the words "Make", "Maker", "Making" and "Made". I think you already have to write "Make(tm)". People who did this use to be "hackers" or "DIY-ers", but now this is catching on. The site/magazine already refers to anyone who creates/hacks anything as a "Maker", basically labeling them with their own trademark.

I wonder is this is even a defensible trademark. Will we need to start using "Creators" as an alternative? Also, isn't "The Maker" already kind of prior a

I don't know where they are sourcing that term, but "Maker" was used extensively by Orson Scott Card in the book 'seventh son'. I imagine it's a term they have adopted for use in the reprap community. Which makes sense, because it's highly applicable.

I'm not sure I've ever heard the term Makers as used in this context. I was pretty much expecting to see Mark come after it, capitalized and everything.

It's quite common lately. Kind of like a more physical version of Hackers. Think of it as a collective term for people who make stuff for fun and perhaps a little profit rather than invent and patent and scream bloody murder if someone brings out something similar. Anything from knitted laptop covers to 3D printing and home CNC.

It's quite common lately. Kind of like a more physical version of Hackers. Think of it as a collective term for people who make stuff for fun and perhaps a little profit rather than invent and patent and scream bloody murder if someone brings out something similar. Anything from knitted laptop covers to 3D printing and home CNC.

I've met the RepRap team and I can tell you the one thing they are best at (and it appears slashdot are helping them replicate) is hype and self publicity.

The RepRap machine is basically a cheap plastic printer / rapid prototyping machine which is an idea that's been around... at least 10+ years before they started. The only component they can manufacture are the plastic bits. Have a look at the photo and see if you can spot the plastic bits. I'll give you a hint, they're not the metal frame, or the woo

I thought the goal was to give it the ability, eventually, to print its own circuits too. Its been a long time since I browsed their page though, so I might be wrong. Off all the bits it can't do now, the wood bits is the only thing a sufficiently advanced 3D printer would not be able to do. Not that the RepRap (gah, the name is dumb) is even near to being that advanced.

Eventually, though, I can see a device that can build its own structural components, and print its own boards. Making its own motors is

The nice thing about being able to produce the plastic bits is that they are the most expensive part. Threaded steel rod is cheap, wood is cheap, standard electrical parts are cheap, but custom-shaped plastic is only cheap if you can do a run of at least a million parts. A one-off run of the plastic bits at the typical prototyping shop will run you about $250, while a RepRap can make them for around $10.

IMHO, this is the kind of inventive tinkering that should be pushed forward in today's schools. It takes a lot of different skills from across several disciplines to be able to crank something like this out, but once you see it, you realize how simple it really is. It takes imagination and perseverance as well, and that's hard to teach.

I don't mean to start a "Public schools are apathizing our youth!" thread, but I wonder how many kids would really enjoy classes geared towards making useful projects out of surplus crap - a combining of wood shop, metal shop, and electronics classes.

I completely agree with everything you are saying. It would work great if our schools were populated with slashdot type students. Unfortunately, reality is otherwise. I think if you spent some time in schools you would be shocked at how apathetic they are when we get 'em.

However, I do think there is a serious problem with the direction schools are going with the use and teaching of technology. The emphasis has been on acquiring more and more computer workstations. Tech education now consists of word, p

That would presumably be the UK. Just substitute 'state school' when you hear Americans talk about 'public schools'.

In the UK, there used to be private schools. These were run as businesses, where people went, paid, and were given an education. Then there were charity schools. These were run by local communities, or often by the church or by a company wanting to develop a region (for example, there were public schools in Wales funded by the mine owners). They were open to anyone, and usually didn't

And that's where everything starts to go wrong. Instead of encouraging the stragglers to catch up, everyone is forced to slow down. In this environment not one slow-poke will make an extra effort - why should he? Whereas more than one above average intelligence student will get frustrated and/or bored and stop paying attention. Only the truly gifted come through such a process unscathed - but because they don't need "school" anyway. Put them next to a pile of books and provide a mentor to answer the occasional question, and they're fine in ANY environment. They live for learning and you can't take it from them.

We do in America, too. By the time kids are eight (well, six, actually) they are grouped by ability. Now, they will mix abilities in classes (i.e. groups of smarts with groups of dumbs sot he teacher can work with one group while the other is doing independent work) until their ten. Once they hit ten or eleven, they get segregated by ability in most subjects, and by the time they are thirteen they are almost completely segregated with the smartest never even seeing the dumbest in a school as small as 200-

Face it, the 10-20% of keen kids that you can really do something with are going to pick up more skills faster from YouTube. High school shop isn't what you're looking for. By necessity the school has got to gear to the slowest.

Schools can and do (or, at least, did, both when I attended and when I worked in them, though the former was two decades and more ago and the latter a decade ago) have classes geared much more narrowly than the top 10% to 20% of the student body. When I went to high school, in a scho

There are lots of laser etching/marking systems that work perfectly well with wood. The one that comes to mind first is Epilog [epiloglaser.com] who make things that are basically desktop printers with an industrial laser, so you put in your piece of whatever and it cuts it. They're fairly cheap, fairly rugged, and do a fantastic job of burning complex patterns into wood. (I know the people who make them, and have used them quite a bit.) They do a fine job with even fairly light woods like Southern Yellow Pine, and if yo

I shall repeat what a wise man said at one time. "I want sharks with freakin lazer beams on their heads!!!!!"
Now make it happen.
or maybe some triceratops with nightvison goggles with laser guns on the side.

The lasers used in eye surgery are fairly different. There are two general types of laser action, burning and ablation. The lasers used in this article are infra-red or red -- which is to say, inexpensive, readily available -- and they remove material by burning it off. You don't really want to be burning stuff off your eyes if you can help it. So the lasers used in eye surgery (and a variety of other heat-sensitive materials) ablate rather than burning: they work in the ultraviolet range, so the photon

So essentially he is making the cut by drilling a series of adjacent holes. Depending on the spacing between the holes the cut may have a very rough finished edge.
If the laser is capable of removing material, the next logical step would be a laser based CNC machine. Basically the reverse of what they are doing with the sintering rig, but using a subtractive process rather than an additive process.

Well, look what the ability to make hundreds of dies simultaneously on a wafer did for the semiconductor revolution. If one could make hundreds of small plastic custom parts at one time, it could enable small businesses to make things they otherwise couldn't do economically. I look at cheap Chinese products and ask, why make them over there and lug them thousands of miles at a cost of energy, when we could do short runs as needed here, locally and by American businesses. I have lots of things around the hou

Well, look what the ability to make hundreds of dies simultaneously on a wafer did for the semiconductor revolution. If one could make hundreds of small plastic custom parts at one time, it could enable small businesses to make things they otherwise couldn't do economically. I look at cheap Chinese products and ask, why make them over there and lug them thousands of miles at a cost of energy, when we could do short runs as needed here, locally and by American businesses. I have lots of things around the house that could have been made by a machine with this technology (layered up). By the way, let's extend the manufacturing principle to not just 2D axes but also rotational, as in what a lathe does but instead of removing material you add it to a rotated base. So for example you could make a cup on demand out of plastic beads fused together - which is just about what a styrofoam cup is.

Eventually perhaps. But right now, injection moulding and other similar techniques are more practical.To use your Styrofoam cup example. The cups take a fraction of a second with a mould. Pop two halves together, pump in the Styrofoam, dry, release. Easy and efficient. Thousands can be made in an hour.
3D object creation is in it's infancy right now. The hardware is expensive and still quite primitive, with a limited number of things it can use as a medium. In time.. Who knows.
Making a cup with a 3D print

Sure, there are more efficient and practical ways but the point of personal manufacturing systems is to be able to make things yourself in small runs instead of depending on large-scale mass production manufacturers. If I have a home box that can make shoes, I might choose to pay a little more for raw materials but I gain the ability to be independent of a specific finished goods maker. Even it is slower than buying off the shelf and it takes two days to process, I don't care if it runs overnight and takes

I think the recycling thing is important. I was really tempted by something like the MakerBot or RepRap when I saw them at FOSDEM, but I knew that my house would quickly fill up with random plastic crap if I had one. On the other hand, if I could just dump stuff I was bored with back in the plastic reservoir and have it melted down for re-using in the next thing I wanted, that would be really great. I'd love, for example, to be able to fabricate the right number of plastic plates, knives, and forks for a

3D object creation is in it's infancy right now. The hardware is expensive and still quite primitive, with a limited number of things it can use as a medium. In time.. Who knows.Making a cup with a 3D printer of any kind would be pretty slow. Fine for one cup, but not for mass production.

Actually you would be surprised, 3D printing [henryschein.com] is the cutting edge in dental technology, but milling is more advanced such as the D4D labworks [e4dsky.com] system that scans, designs and mills, Wieland [henryschein.com]manufacture milling machine that is more production orientated. The industry is moving toward digital from beginning to end by using intraoral scanners and not even taking traditional impressions; the biggest holdup is capitalization of equipment systems that often costs 6 figures.